Shore Power Pedestals

I have a project that consist of existing shore power pedestals on a commercial dock. The customer is experiencing troubles, once the tide gets extremely high and over the dock, the pedestals get submerged under water. The question is about 2- 50amp pedestals being powered by a 100amp 240v breaker, and when the water reaches the studs on the pedestal, the 100 amp breaker does not open up. The breaker is a 100amp CH 240v 10AIC Rated Breaker. What breaker type could we suggest to use in order for these breakers to open up? There are approximately 10- 100amp breakers and 20- 30amp breakers on the dock. We will use 30amp GFCI breakers to correct the 30amp pedestals, but the 100amp breakers do not come in as GFCI breakers.

It sounds like the installation is in violation of the NEC, as the electrical equipment is located below the datum plane, as defined in Article 682. I would suggest that the installation be re-done to meet Article 682. PS - This is a big deal, and an electrocution hazard.